UVA12560 Good Friends

Description

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=441&page=show_problem&problem=4005 [PDF](https://uva.onlinejudge.org/external/125/p12560.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12560/42d1822156ad3a0748a3a91134b08857db60e4b3.png)

Input Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12560/9c22bc946b8e8727db4daef3d1f53ef4f3b0731c.png)

Output Format

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12560/de505de115b6c7450fce86ddcb808d6baf84a454.png)